They were an evolution from the preceding Myoko-class, with heavier torpedo armamanent and had an almost battleship-like, large bridge structure.
United States Navy recognition drawings of Takao and Atago
Their main gun armament was ten 20 cm (8 in) guns in twin mounts and they were also armed with sixteen 24 inch Long Lancetorpedoes (carrying more than the Myokos or Mogamis), making the Takaos the most heavily armed cruisers of the IJN. The only flaw was that they were considered top-heavy and thus prone to capsizing, while Turret #3 had a poor firing arc. These two problems were rectified in the follow-up Mogamis; nonetheless the Takaos were considered the best cruisers that the IJN ever built.
Takao class midship with armour thickness in millimetres